title: Effects of melatonin on superovulation and transgenic embryo transplantation in small-tailed han sheep (Ovis aries).
abstract: OBJECTIVE
  In this study, the effects of melatonin on superovulation and the transfer of transgenic embryos were investigated in Small-Tailed Han sheep.
  
  
  METHODS
  Different doses of melatonin (0, 40 or 80 mg/animal) were subcutaneously implanted into both multiparous (4-5 years old) donors and recipients before superovulation and estrus synchronization. The one-year-old young ewes without melatonin treatment served to evaluate the reproductive efficiency of the adult multiparous ewes. Ewes with superovulation were used as embryo donors. The estrus were induced in embryo recipients after embryo transpimplanted.
  
  
  RESULTS
  The results showed that the number of corpora lutea of the ewes received subcutaneous 40 or 80 mg melatonin implant (13.4±1.05/ewe, 15.1±1.62/ewe) were significantly higher than that of in control group (8.8±0.37/ewe) (p<0.05). Similarily the number of recovered embryos from the ewes received subcutaneous 40 or 80 mg melatonin implant (10.3±0.84/ewe, 10.9±1.21/ewe) was significantly higher than the control group (6.2±0.60/ewe) (p<0.05). The transimplantd embryos from 40 or 80 mg melatonin treated donors dramatically improved the pregnancy and birth rates compared to control ewes. In addition, both 40 mg and 80 mg melatonin implatation lead to more lambs born per embryo.
  
  
  CONCLUSIONS
  These observations provide valuable information for the application of melatonin in increasing superovulation and transgenic embryo transplantation efficiency in sheep.
authors.affiliation: College of Animal Science and Technology, China Agricultural University, Beijing 100193, China. gshliu@cau.edu.cn
authors.forename: Lu
authors.initials: L
authors.lastname: Zhang
authors.forename: Menglong
authors.initials: M
authors.lastname: Chai
authors.forename: Xiuzhi
authors.initials: X
authors.lastname: Tian
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.forename: Yao
authors.initials: Y
authors.lastname: Fu
authors.forename: Changjiu
authors.initials: C
authors.lastname: He
authors.forename: Shoulong
authors.initials: S
authors.lastname: Deng
authors.forename: Zhengxing
authors.initials: Z
authors.lastname: Lian
authors.forename: Jiangzhong
authors.initials: J
authors.lastname: Feng
authors.forename: Dun-Xian
authors.initials: DX
authors.lastname: Tan
authors.forename: Guoshi
authors.initials: G
authors.lastname: Liu
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D000975:Antioxidants / Q000494:pharmacology*; D003338:Corpus Luteum / Q000187:drug effects; D010064:Embryo Implantation / Q000187:drug effects*; D004624:Embryo Transfer / Q000662:veterinary; D004622:Embryo, Mammalian / Q000187:drug effects*; D005260:Female; D005818:Genetic Engineering / Q000662:veterinary; D008550:Melatonin / Q000494:pharmacology*; D011247:Pregnancy; D034561:Sheep, Domestic / Q000235:genetics; D013480:Superovulation / Q000187:drug effects*
chemical_list: D000975:Antioxidants; D008550:Melatonin